High stress and fracture of silicon crystalline solar cells has recently been observed in increasing percentages especially in solar photovoltaics (PV) modules involving thinner silicon solar cells (<200 um). Many failures due to fracture of cells have been reported from the field and handling. However, a significantly higher number of failures have also been reported during module integration (soldering/ stringing and lamination) indicating a PV laminate/module with significantly high residual stresses and hence more prone to cell fractures. We characterize the residual stress evolution in crystalline silicon solar cells during module integration process, which is the current knowledge gap. The residual stress characterization was achieved through a systematic research using synchrotron X-ray submicron diffraction experiments coupled with physics-based Finite Element modeling of the PV module integration process. Thought this work we also demonstrate the unique capability of Synchrotron X-ray submicron diffraction to quantitatively probe residual stress in encapsulated silicon solar cells that has ultimately enabled these findings leading to the enlightening of the role of soldering and encapsulation processes. While our experiments quantify the stress at different process states including encapsulated cells, our FEA simulations, for the first time unravel the physical reasoning for the stress evolution and expected to bridge the knowledge gap. This model can be further used to suggest methodologies that could lead to lower stress in encapsulated silicon solar cells, which are the subjects of our continued investigations.

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